ELEMENTARY STATISTICS: A STEP BY STEP APPROACH is for general beginning statistics courses with a basic algebra prerequisite. The book is non-theoretical, explaining concepts intuitively and teaching problem solving through worked examples and step-by-step instructions. This edition features increased emphasis on Excel, MINITAB, and the TI-83 Plus graphing calculator, computing technologies commonly used in such coureses.

"Technology Step by Step" sections show how to solve basic problems using Minitab software, the TI-83 Plus graphing calculator, or Excel.

Statistics Today problems open every chapter. These real-life problems, accompanied by a photo or graphic and sometimes a news item, show students the relevance of the chapter's topic. The answer is provided at chapter end.

Procedure Tables embody the book's step by step approach. These boxes summarize methods for solving various types of common problems. Worked examples include EVERY step.

Critical Thinking Challenges at the end of each chapter extend chapter concepts into new areas, inviting students to think about and apply what they have learned.

Section 13-3, on the Scheffe Test and the Tukey Test, covers material not available in some other introductory statistics texts. These topics can be important in a two-semester course or a course emphasizing research methods.

9 Testing the Difference Between Two Means, Two Variances, and Two Proportions

9-1 Introduction 9-2 Testing the Difference Between Two Means: Large Samples 9-3 Testing the Difference Between Two Variances 9-4 Testing the Difference Between Two Means: Small Independent Samples 9-5 Testing the Difference Between Two Means: Small Dependent Samples 9-6 Testing the Difference Between Proportions 9-7 Summary

ELEMENTARY STATISTICS: A STEP BY STEP APPROACH is for general beginning statistics courses with a basic algebra prerequisite. The book is non-theoretical, explaining concepts intuitively and teaching problem solving through worked examples and step-by-step instructions. This edition features increased emphasis on Excel, MINITAB, and the TI-83 Plus graphing calculator, computing technologies commonly used in such coureses.

"Technology Step by Step" sections show how to solve basic problems using Minitab software, the TI-83 Plus graphing calculator, or Excel.

Statistics Today problems open every chapter. These real-life problems, accompanied by a photo or graphic and sometimes a news item, show students the relevance of the chapter's topic. The answer is provided at chapter end.

Procedure Tables embody the book's step by step approach. These boxes summarize methods for solving various types of common problems. Worked examples include EVERY step.

Critical Thinking Challenges at the end of each chapter extend chapter concepts into new areas, inviting students to think about and apply what they have learned.

Section 13-3, on the Scheffe Test and the Tukey Test, covers material not available in some other introductory statistics texts. These topics can be important in a two-semester course or a course emphasizing research methods.

9 Testing the Difference Between Two Means, Two Variances, and Two Proportions

9-1 Introduction 9-2 Testing the Difference Between Two Means: Large Samples 9-3 Testing the Difference Between Two Variances 9-4 Testing the Difference Between Two Means: Small Independent Samples 9-5 Testing the Difference Between Two Means: Small Dependent Samples 9-6 Testing the Difference Between Proportions 9-7 Summary